/// map-sort
/// Sort map by keys
/// @param $map - A SASS map
/// @returns A SASS map sorted by keys
/// @requires function list-sort
/// @author Jake Wilson <jake.e.wilson@gmail.com>
@function map-sort($map) {
    $keys: list-sort(map-keys($map));
    $sortedMap: ();
    @each $key in $keys {
        $sortedMap: map-merge($sortedMap, ($key: map-get($map, $key)));
    }
    @return $sortedMap;
}